Sediment in Peninsula Harbour is contaminated by mercury and polychlorinated biphenyl (PCBs) from historical discharges of wastewater and storm water runoff from the local pulp mill, which closed in 2009. A 15-20 centimetre layer of clean sand will be placed on top of the contaminated sediment. This is said to accelerate natural recovery of Jellicoe Cove in Peninsula Harbour by reducing plant, animal and fish exposure to chemicals in the sediment, and the spread of contaminated sediments from Jellicoe Cove to the rest of the harbour. This is the first time that a thin-layer capping will be used to manage contaminated sediments in Canada.

Ontario’s funding for the Peninsula Harbour sediment capping project includes a $3 million settlement from a former owner of the pulp mill, Ball Packaging Products Canada Corp., and $1.6 million in provincial funding.